1. Field of the Invention
The present invention relates to a method of forming a rare earth-iron-garnet vertically magnetized film and, more particularly, to a method using a chemical process for forming a rare earth-iron-garnet vertically magnetized film having magnetic properties usable for an optomagnetic recording medium on any substrate.
2. Description of the Prior Art
In a known conventional chemical method of forming a rare earth-iron-garnet film, a concentrated solution containing Gd and Fe ions in an ion ratio of 3:5 is diluted with ethyl alcohol to prepare a coating solution. After the coating solution is spin-coated on an yttrium aluminum garnet (YAG) substrate, the coated film is dried at 300.degree. to 500.degree. C. and then heated in air at 650.degree. C. so as to epitaxially grow Gd.sub.3 Fe.sub.5 O.sub.12 on the YAG substrate. This method thus comprises a chemical process to form a rare earth-iron-garnet film.
This conventional chemical method has an advantage that a rare earth-iron-garnet film of single crystals having excellent magnetic properties can be formed on a single crystal substrate such as a YAG or GGG (gadolinium gallium garnet) substrate. In such a conventional method, however, a film having vertical magnetic properties can be formed only on a single crystal substrate as described above, and a film having in-plane magnetic properties can only be manufactured if an amorphous substrate such as a glass substrate is used.
The fact that substrate materials for allowing formation of vertical magnetized films are limited to single crystals means that the industrialization is difficult owing to poor productivity and high cost of single crystal substrates.